Accuracy of primary care and hospital-based physicians' predictions of elderly outpatients' treatment preferences with and without advance directives

Background: Past research has documented that primary care physicians and f amily members are often inaccurate when making substituted judgments for pa tients without advance directives (ADs). This study compared the accuracy o f substituted judgments made by primary care physicians, hospital-based phy sicians, and family surrogates on behalf of elderly outpatients and examine d the effectiveness of ADs in improving the accuracy of these judgments. Participants and Methods: Participants were 24 primary care physicians of 8 2 elderly outpatients, 17 emergency and critical care physicians who had no prior experience with the patients, and a baseline comparison group of fam ily surrogates. The primary outcome was accuracy of physicians' predictions of patients' preferences for 4 life-sustaining treatments in 9 hypothetica l illness scenarios. Physicians made substituted judgments after being prov ided with no patient AD, patient's value-based AD, or patient's scenario-ba sed AD. Results: Family surrogates' judgments were more accurate than physicians'. Hospital-based physicians making predictions without ADs had the lowest acc uracy. Primary care physicians' accuracy was not improved by either AD. Acc uracy and confidence in predictions of hospital-based physicians was signif icantly improved for some scenarios using a scenario-based AD. Conclusions: Although ADs do not improve the accuracy of substituted judgme nts for primary care physicians or family surrogates, they increase the acc uracy of hospital-based physicians. Primary care physicians are withdrawing from hospital-based care in growing numbers, and emergency medicine and cr itical care specialists most often are involved in decisions about whether to begin life-sustaining treatments. If ADs can help these physicians bette r understand patients' preferences, patient autonomy more likely will be pr eserved when patients become incapacitated.